Scanning devices refers to devices that utilize a magnetic or photoelectric source (e.g., a light-emitting diode) to sense and convert an image into corresponding electric signals for processing by an electronic apparatus. The image converted includes text, graphics, and pictures. Images may be color or black and white. Scanning devices are used, for example, to convert a document to an electronic file, or a photographic image to an electronic graphic file. Other uses for scanning devices include sensing an image to be sent over a voice frequency circuit (facsimile device) or to be reproduced (copier device).
There are generally two types of scanning devices. The first type of scanning device is the flat-bed scanner that operates by placing a document with an image on the scanning device housing and a motor-driven scanning device makes a pass or several passes across the document to sense the image. The other type of scanning device is a manually operated scanning device wherein a hand-held scanning device is directed over a document containing an image by a user or operator. The scan head is located on the bottom of the manually operated scanning device and scans an image as the scanning device is dragged over the image. For example, an image that is a document is converted into corresponding electric signals by dragging the scanning device from the top of the document, line by line, to the bottom of the document.
The scan head of the manually operated scanning device is located on the bottom of the scanning device so that the operator of the scanning device cannot see precisely the image being scanned. The manually-operated scanning device typically contains horizontal and vertical grids or marks on the top opaque surface of the scanning device to act as a reference to direct the operator to the location of the scan head mechanism and the image being scanned at a particular time. The horizontal and vertical grids are the only reference to a user of the location of the scan head mechanism over an image. These grids or marks in the opaque housing of the scanning device are difficult to see because of low contrast between the grids and the housing. A user must pay close attention to maintain the horizontal and vertical grids on precisely the image being scanned at a particular time. Even inputting a simple image on a document with a manually-operated scanning device with grid guide marks can be tedious due to the attentiveness required to scan the document accurately. Thus, there is a need for a manually-operated scanning device that provides grids or marks with high contrast to facilitate and encourage proper alignment of the image being scanned and make the scanning operation less tedious.